Research On Spacecraft Attitude Stabilization Based On Adaptive Fuzzy Sliding Mode Control

Spacecraft attitude control is one of the key problems of spacecraft control, as a part of the attitude control, attitude stabilization is also the research focus of spacecraft control. Because of MIMO, strong coupling, external interference characteristics of spacecraft attitude control system, in the same time, uncertainty of parameter and disturbance make the spacecraft attitude control problem more complicated. In order to reach the designated position within the specified time, the focus of this paper is to design a adaptive fuzzy sliding mode controller while we don’t need decouple the system and make sure the upper bound of disturbance.First of all, this paper introduces the the definition, basic characteristics and shortcomings of sliding mode variable structure control, which prepares the mathematical foundation for designing a sliding mode controller, then the paper introduces the mathematical description of spacecraft attitude control, which is including the coordinate system and the common way of describing, then gives the spacecraft attitude dynamic mechanics and kinematics equation, which builds the model for the following.Then the paper designs a spacecraft attitude stabilization controller which is based on sliding mode variable structure control at first, then proves the stability.of the system by using the Lyapunov direct method. Simulation results show that in the condition of the bounded disturbance, the controller is designed within the specified time to the specified location, and the amplitude of chattering is very small. Thedesign meets the design requirements.The controller designed based on sliding mode control need to know the upper bound of disturbance, which limits the application of sliding mode variable structure in spacecraft attitude stabilization. In order to solve this problem, this paper designs the adaptive fuzzy sliding mode variable structure controller. Firstly, the paper introduces the basic concept of fuzzy control, then designs a adaptive fuzzy sliding mode controller for general nonlinear system, and the designed controller is applied to spacecraft attitude stabilization, and gives the theoretical proof, simulation results prove that the adaptive fuzzy sliding mode controller can achieve the control objectives while does not need to be decoupled, and it also can reduce the reaching time, weaken the chattering.